Photographic developing apparatus



Nov. 8, 1960 F. H. M CLERNON PHOTOGRAPHIC DEVELOPING APPARATUS Filed May 24, 1956 FIflZwiB-HJ ICO IJGPHOZL, 6% @3144 EZM/w ATTORNEYS United States Patent PHOTOGRAPHIC DEVELOPING APPARATUS Francis H. McClernon, 2nd Floor, Optical Bldg., Springfield, M0.

Filed May 24, 1956, Ser. No. 587,138

7 Claims. (Cl. 9590.5)

This invention relates to apparatus for processing photographic film, and more particularly to an apparatus for the sequential processing of long strips of photographic film.

It is an important object of the present invention to provide a new and improved design for the developing receptacle or tank and the film-carrying reel adapted for rotation therein whereby the amount of each of the developing liquids to be used is minimized.

Another object is to provide a new and improved design for the developing receptacles or tanks which will enable such receptacles to be nested in small stacks when not in use, whereby little space will be needed for storage purposes.

A further object is to provide a novel film-carrying reel which will permit film strips to be attached thereto quickly and easily in optimum arrangement for processing without the necessity of observing the film as the latter is placed on the reel.

A still further object of this invention is to provide a film-carrying reel which may be rotatably associated with a developing receptacle lid to form an easily handled assembly. A related object is to provide a film reel and receptacle lid assembly movable as a unit from receptacle to receptacle, for convenient sequential film processing.

An additional object is to provide a developing apparatus for photographic film which is simple in construction, inexpensive to manufacture and easy to operate.

Other object will be in part obvious, and in part pointed out hereinafter.

The invention and novel features thereof may best be made clear from the following description and the accompanying drawing, in which:

Figure l is a sectional elevational view of an exemplary embodiment of the present invention, with some of the parts thereof partly broken away;

Figure 2 is a fragmentary, sectional view taken along line 2-2 of Fig. 1;

Figure 2a is a fragmentary, plan view of the film-carrying reel of Figure l, on an enlarged scale, and showing the manner in which a film strip is attached thereto.

'Figure 3 is a fragmentary, elevational view of the filmcarrying reel of Fig. l, with a section of a film strip attached thereto;

Figure 4 is a fragmentary plan view of a modified form of film-attaching means for the reel; and

Figure 5 is a fragmentary, sectional elevational view of another modified form of film-attaching means for the reel.

Referring to the drawing, an exemplary embodiment of the present invention comprises a developing receptacle or tank 10, a lid or cover 30 for the receptacle, and a reel or spool 50 disposed in the receptacle and adapted to be associated with the lid 30.

The receptacle is intended to hold a supply of photographic film-processing liquid, and is preferably made from a tough plastic, although any suitable plastic, metal, glass or the like may be used. In processing photographic film, several receptacles 10 will be arranged in sequence, each containing a different liquid adapted for carrying out a different step in the developing operation. For example, receptacles may be provided containing a developing liquid such as a combination of hydroquinone and metol, a fixing liquid such as sodium thiosulfate, and a washing or rinsing liquid such as water.

The receptacle 10 is formed with upwardly and outwardly tapering side walls 12, preferably of circular configuration in transverse section. The top of side walls 12 may be thickened or enlarged to form a bead 14 which strengthens the side walls against distortion by lateral forces. The side walls 12 terminate at their lower ends in an integral closed bottom 15 formed with a central, conical recess or concavity 16. Concavity 16 extends a considerable distance upwardly in the receptacle 10, as seen in Figure 1. By reason of the tapering Walls 12 and concave bottom 15, similar receptacles may be nested or stacked one within another, with each nested receptacle substantially completely received within its enclosing receptacle. In this manner, many like receptacles may be compactly nested for convenient handling and for storing in relatively small spaces.

The receptacle lid 30 is of generally circular shape in plan view, and includes a circular boss 32 having a central aperture 34 therein. Depending from lid 30 at the periphery thereof, is a flange 35 formed with a radial surface 36 and an axially extending portion 37 of reduced thickness, being disposed at the inner end of the surface 36. The extension 37 has an outer tapered surface 39 adapted for cooperation with the radial surface 36 to permit the extension 37 to be removably fitted within and frictionally engaged by the open top end of the receptacle 10 for retaining the lid thereon. The surfaces 36, 39 are generally complementary to the top and inner surfaces of the receptacle side walls 12, as seen in Figure 1, to facilitate attaching the lid to the receptacle.

' The reel 50 is hollow and preferably is made of plastic, being of uniform thickness throughout, and formed to define a conical helix or spiral on both the exterior and interior thereof. Any convenient casting or stamping process or the like may be employed in producing the hollow reel 50. The external helix of the reel preferably comprises a helical vertical wall 64 and a helical, gradually inclined wall 66 integral therewith. The coils or turns in the helical walls gradually decrease in diameter, ascending the helix, to present a generally conical outline to the reel, which outline is substantially complementary to the receptacle concavity 16 for a purpose hereinafter to become apparent.

Disposed on the exterior of the vertical helical wall 64 of the reel are a plurality of radially outwardly projecting lugs 68, being of circular disc-like conformation and arranged at equally spaced points along the entire helical length defined by said vertical wall, as best seen in Figures 2 and 3. A film 69 having perforations 71 in unsensitized edges or margins 73 may be attached to reel 50 in the following manner. The circular lugs 68 on the reel are preferably of a diameter approximately as large as or slightly larger than the width of each film perforation and are spaced apart a distance equal to the distance between two or more perforations. Starting at either the innermost or the outermost turn in the vertical helical wall 64, the perforations in the film are fitted or snapped over lugs 68 and as the film is wound on the reel helix, it is pulled in the direction of winding to dispose a vertical edge of the film perforation behind each lug and in wedged frictional engagement with the converging surfaces of the lugs and wall 64, as seen in Figures 2, 2a and 3, whereby the film will be securely held on the reel.

The upper end of reel 50 is closed by a top wall 67.

A shaft 52 is arranged in a central aperture in the wall 67, projecting upwardly therefrom, and is suitably associated with the reel 50 so that rotary power may be transmitted thereby to the reel 50. The shaft 52 may be provided with a circular foot portion 53 adapted to be connected to the reel top wall 67 by screws or the.

like, while the upper end of the shaft has a pair of di; ametrically opposed projecting pins or lugs 63 thereon.

A driving means 54 for the reel shaft 52 is provided in the lid 30. This driving means comprises a vertical shaft 56 disposed in the lid aperture 34 and also comprises a horizontal crank arm 55 removably secured to shaft 56 and having a finger-engaging knob 57 at the outer end thereof. A female coupling structure 61 for the reel shaft 52 forms an enlargement on the lower end of the shaft 56. This coupling structure 61 may be of the bayonet-joint type, comprising the customary inverted L-shaped slots,65. The top of the reel shaft 52 may be drivingly coupled to shaft 56 by inserting the pins 63 of the former in the slots 65 and then rotating shaft 52 to dispose pins 63 in the horizontal'portion of the L-shaped slot 65. Rotation of crank arm 55 in the opposite direction will now be effective to rotate the shaft 52 and reel 50. In this manner, the reel 50 may be quickly and easily drivingly attached to the lid 30, resulting in a conveniently handled combined structure. A shim or washer 62 is secured within the lid boss 32 as shown, by means of screws or the like, for cooperating with the enlarged structure 61 on shaft 56 and an annular shoulder 58 on the crank arm 55 to prevent excessive relative axial movement between the driving means 54 and the lid 30.

It should be observed that after the lid and reel have been assembled and the lid placed on the receptacle 10, the reel 50 will be disposed adjacent the receptacle concavity 16, substantially completely surrounding the latter.

When it is desired to process a roll of film, the film is first attached to the reel 50 in the manner described hereinabove. The reel is then connected to the driving means 54 on the lid 30 and a plurality of receptacles are filled with the various developing, fixing and washing liquids to be used. The combined lid and reel assembly is then attached to the receptacle containing the developing liquid with the lid engaging the receptacle top as seen in Figure 1. The reel 50 is suspended in the receptacle adjacent the bottom 16 thereof so that the film on the reel will be disposed completely below the top of the receptacle, whereby the receptacle need not be completely filled with liquid to-immerse the entire roll of film on the reel.

After the combined lid and reel have been attached to the developing receptacle, the crank 55 is turned by hand to rotate the reel in the developing liquid for the desired period of time. It will be noted that the vertical and inclined helical walls 64, 66 are of such size that only the unsensitized film edges 73 contact the vertical Wall 64 and each turn of the film is spaced a sufiicient distance from an adjacent turn to permit freev contact of both sides of the film, in the sensitized area, by the liquid in the receptacle. By virtue of this construction, whereby the complete surface of each side of the film, in the sensitized area, will be contacted by the processing liquid, the film may be attached to the reel in a dark room where there would be no opportunity to observe the placing of the film on the reel and yet the film will always be in a position for complete processing since it is immaterial which edge thereof is associated with the lugs 68 and which side thereof is facing outwardly.

During the rotation of the reel 50, the film carried thereby will be rotated within the body of developing liquid to effect the desired Wiping and agitating action of the. liquid over the: surface of, the film. Due-to the fact that the perforated edgesrof' the; film have. been pulled tightly between the converging surfaces ofthe reel.

4 lugs 68 and vertical wall 64 there will be little danger of the film becoming detached from the reel.

It will be observed that the amount of liquid in the receptacle 10, necessary to completely cover the film on the reel, is considerably less than that which would be necessary if the bottom of the receptacle were flat. Therefore, in addition to facilitating the nesting of like receptacles in small stacks, the design of the receptacle 10 permits the use of a relatively small quantity of liquid without impairing the efiiciency of the developing operation.

After the film has been rotated in the developing liquid for the desired length of time, the lid 30, carrying the reel and film, is lifted from the receptacle and may be shaken thereabove to drain any excess liquid from the various parts. The combined lid and reel is then attached to a receptacle containing a washing liquid to assure a more complete removal of any developing liquid remaining on the film. When the washing operation has been performed, the combined lid and reel is transferred to another receptacle containing a fixing liquid and rotated therein in the manner described above. The next step involves a final washing of the film in still another receptacle. This final washing receptacle may be provided with an upper liquid inlet fitting connected to a water supply and a lower drain or outlet fitting whereby a continuous flow of water may be effected through the receptacle to guarantee the complete removal of any undesirable compounds from the film.

It should thus be apparent that the combined lid and reel assembly presents a conveniently handled structure that may be readily transported between receptacles thereby facilitating the processing of the film.

If desired, the shafts 52 and 56 for driving the reel 50 may be made integral and the lower portion of shaft 52 may then be removably connected to the top wall 67 of the reel by any suitable expedient such as a bayonettype joint. Additionally, an electrical motor and timer unit may be provided on the lid 30 to rotate the crank 55.

In lieu of the circular lugs 68 for attach-ing the film to the reel 30, these lugs may be constructed to have a semi-circular shape, in plan view, as the lugs 70 in Figure 4. These lugs 70 are connected'to the vertical wall 64 and spaced radially outwardly therefrom by an integral stem 75 on each lug, whereby the edges of the film perforations 71 may be pulled into a locked position in the space between the back of the lugs and the wall 64, as seen in Figure 4.

Another modification of the means for attaching film to thereel is shown in Figure 5. This modification involves the use of longitudinally-curved spring clips 72, connected to and equally spaced along the outer surface of the inclined helical wall 66. These clips are biased against vertical wall 64 for frictionally engaging the edge of a film strip and are particularly adapted to retain unperforated film on the reel. 7

It will thus be seen that there has beenprovided, by this invention, a structure in which the various objects hereinabove set forth, together with many practical advantages, are successfully achieved. As various possible embodiments, may be made of the mechanical features of the above invention, all without departing from the scope thereof, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawing is to be interpreted as illustrative, and not in a limiting sense.

I claim:

1. Photographic film developing apparatus comprising, a receptacle for containing photographic film-treating liquid, said receptacle having an open top, side walls and a closed, concave bottom, a detachablerlid for said open top, a hollow film-carrying reel disposed in said receptacle, means for rotatably suspending said reel from said lid. forrotation of ,said reel relative to said lid, said reel including an; external conical helix, said reel having an interior generally complementary to the receptacle bottom and disposed adjacent thereto and thereabove, and said reel being disposed completely out of engagement with any part of said receptacle or said lid.

2. The structure defined in claim 1 wherein means are provided on the external helix of the reel for attaching a roll of film thereto.

3. The structure defined in claim 2 wherein the external conical helix of the reel is defined by a vertical helical surface defining turns of progressively decreasing size in an upward direction, and an inclined helical surface extending transversely between turns of said vertical surface.

4. The structure defined in claim 3 wherein the means for attaching film to the reel comprises a plurality of spring clips arranged at equally spaced points along the extended helical length of the inclined surface, said clips being normally biased against said vertical surface and being adapted to engage an edge of the film.

5. The structure defined in claim 3 wherein the means for attaching the film to the reel comprises a plurality of lugs spaced equally along the extended helical length of the vertical surface, said lugs projecting at right angles from said latter surface and being adapted to be inserted in and engage perforations on the edges of the film.

6. Photographic film developing apparatus comprising a receptacle for containing film-treating liquids, a detachable lid for said receptacle, a film-carrying reel disposed in said receptacle, and means for rotatably suspending said reel from said lid for rotation of said reel relative to said lid, said receptacle including upwardly and outwardly tapering side walls, said walls terminating in an open top and a closed, concave bottom to permit nesting of like receptacles when not in use, said reel including an integral, solid body portion having an external conical helix and a hollow interior, the interior of the reel being generally complementary to the concave bottom of said receptacle and disposed adjacent thereto and thereabove, and said reel being disposed completely out of engagement with any part of said receptacle or said lid, and means on said reel helix for attaching a roll of film thereto.

7. The structure of claim 6 wherein the conical helix on the reel is defined by a vertical helical surface defining turns of progressively decreasing diameter in an upward direction, and an inclined helical surface extending transversely between turns of said vertical surface, and wherein the means for attaching film to the reel comprises a plurality of elements mounted on and spaced equally along the extended helical length of one of said surfaces.

References Cited in the file of this patent UNITED STATES PATENTS 673,295 Segna Apr. 30, 1901 815,300 Lindquist Mar. 13, 1906 816,392 Smith Mar. 27, 1906 1,496,631 Henry June 3, 1924 2,194,603 Lingg et al Mar. 26, 1940 2,243,453 Busse May 27, 1941 2,499,348 Alberts et al. Mar. 7, 1950 2,804,003 Hoffman Aug. 27, 1957 2,835,181 Seeley May 20, 1958 FOREIGN PATENTS 209,804 Great Britain Jan. 14, 1924 289,833 Great Britain Oct. 28, 1929 520,123 Germany Mar. 7, 1931 693,965 Germany July 22, 1940 560,005 Great Britain Mar. 15, 1944 956,096 France July 11, 1949 

